This invention relates to a rotary tiller apparatus for mounting on a tractor so as to extend outwardly to one side of the tractor.
Various previous designs have been manufactured for a rotary tiller apparatus of the type which includes a head rotatable about a vertical axis which drives a plurality of tines around the axis for engaging the ground in a weeding action. With the device projecting outwardly to one side of the tractor, the tractor can move forwardly so the device operates along a row. In many cases, however, it is desirable to move the device in and out relative to the tractor so that the head can weed around various obstacles such as trees.
Various previous designs are shown in the following U.S. Patents which have been identified by a search carried out in the U.S. Patent Office; U.S. Pat. No. 2,805,612 (Beard); U.S. Pat. No. 4,332,299 (Parks); U.S. Pat. No. 4,287,955 (Anderson); U.S. Pat. No. 3,190,364 (Maloney); 3,200,890 (Courtway); U.S. Pat. No. 3,117,632 (Caggiano); U.S. Pat. No.: 3,138,208 (Simms); U.S. Pat. No. 4,518,043 (Anderson); U.S. Pat. No. 4,544,038 (Schonert); U.S. Pat. No. 4,491,183 (Anderson).
Many of these devices obtain movement of the tiller head in a direction inwardly and outwardly of the tractor by pivoting a lever supporting the head about a vertical axis. This causes the head to move in a direction which is on an arc of a circle rather than in a straight line which makes it more difficult to control and prevents it from accurately weeding around an obstacle such as a tree. The Anderson patents show an arrangement in which movement inwardly and outwardly is obtained by pivoting of a lever about two horizontal axis so that the device moves generally inwardly and outwardly in a direction at right angles to the tractor side. However the movement of the lever also causes the device to be raised and lowered while it is moved inwardly and outwardly thus affecting the tilling action.
None of these devices have been found to be entirely satisfactory and alternate designs are required preferably one in which the movement of the tiller head is obtained in a straight line direction projecting outwardly to one side of the tractor without affecting the height of action of the tiller head. Furthermore, the mounting and drive to the previous devices from the supporting tractor has been unsatisfactory for application of the device to smaller type "yard" tractors.